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Ducati 125 Marianna Sport

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'The Gran Sport, particularly in 100 and 125cc versions, was incredibly successful between 1955 and 1958, and even after it was replaced by the F3 many riders in Italy continued to campaign the Gran Sport. As it was hand-built and produced in very small numbers for Italian racing, the Gran Sport is rarely seen today outside Italy.' – Ian Falloon, 'Standard Catalog of Ducati Motorcycles'.

Designed by newly arrived engineer, Fabio Taglioni, formerly with Mondial, Ducati's first overhead-camshaft single - the 100 Gran Sport, nicknamed 'Marianna' - appeared on the racetrack in 1955. The existing 98cc overhead-valve engine had reached the limit of its development, at least as far as racing was concerned, hence the need for a design with greater potential. The Gran Sport's overhead cam was driven by a vertical shaft and bevel gears, and this method was carried over to Ducati's twin-cam (bialbero) and triple-cam (trialbero) racers, the latter featuring Taglioni's famous 'desmodromic' method of valve actuation that dispensed with springs. Incorporating a four-speed gearbox, the Gran Sport engine was carried in a simple single-downtube frame and acted as a stressed member.
Apart from the Italian Grand Prix, the most important motorcycle races in Italy at this time were the long-distance events, held on public roads, such at the Moto Giro d'Italia and Milan-Taranto. Hence even competition-orientated models like the Marianna had to have lights and a horn, as required by the FMI (Italian Motorcycle federation) regulations. Almost all the Italian manufacturers contested these events, victory bringing with it much valuable publicity. Ducati's overhead-valve racers had been outclassed by the Laverdas in 1954, but from the time of its arrival the Marianna proved unbeatable in its class.

Source bonhams.com